The accuracy of bubble level is usually high and can meet general measurement needs. Although its accuracy may be affected by bubble size and observer judgment ability, through reasonable design and use, relatively accurate measurement results can still be obtained. The bubble level has good stability during the measurement process and is not easily affected by external factors. This enables it to maintain high reliability even in situations where high-precision measurements are required.

The working principle of the bubble level is based on the surface tension and gravity of the liquid. When the bubble level is placed on the surface to be measured, the liquid will be evenly distributed between two disks, and the bubbles will move to the highest point of the liquid, which is the horizontal position. If the surface is not horizontal, the bubble will deviate from the central position due to gravity, and the surface's levelness can be determined by observing the position of the bubble.